Hubble’s New UV Eyes See The Deep Universe In ‘living Color’

Astronomers using the Hubble Space Telescope have captured the most comprehensive picture ever assembled of the evolving universe and one of the most colorful. The study is called the Ultraviolet Coverage of the Hubble Ultra Deep Field (UVUDF) project. Credit: NASA/ESA/ H. Teplitz and M. Rafelski, A. Koekemoer, R. Windhorst and Z. Levay

Back in the 1960s when color TV programming was cutting edge, NBC-TV’s “Living Color” Peacock logo and announcement made sure we knew it. To the sound of trilling woodwinds and harp glissandos, the announcer would tell us that: “The following program is brought to you in living color on NBC.”

Time to bring back that peacock. Take a look at the Hubble Space Telescope’s revised Ultra Deep Field Image above and compare it to the one below — I think you’ll agree that living color’s back in a big way.

Here’s the original Ultra Deep Field showing nearly 10,000 galaxies. The image required 800 exposures in visible and infrared light taken over the course of 400 Hubble orbits around Earth. The total amount of exposure time was 11.3 days. Notice how much ‘warmer’ and less intense the galaxies appear compared to the new one with the added dimension of UV light. Credit: NASA/ESA

Called the Ultraviolet Coverage of the Hubble Ultra Deep Field (UVUDF) project, astronomers used the Hubble’s Widefield Camera 3 to rephotograph the original field, a tiny patch of sky in the constellation Fornax as wide as what you’d see staring through an 8-foot-long soda straw. It was originally photographed in visible and infrared (dust penetrating) light. This time around ultraviolet filters were used to reveal a brand new dimension not only of color but also of star formation.

An edge-on spiral galaxy collides with a small, young blue galaxy in this detail from the original Hubble UDF. Credit: NASA/ESA

The hottest, most massive and youngest stars, which emit light in the ultraviolet portion of the spectrum and are keys markers of star formation, are a meek presence in the original which covered only visible and infrared light. The new view stretches all the way from ultraviolet to near-infrared light and required 841 orbits of telescope viewing time. With it, astronomers now have a much clearer look at star formation in distant galaxies.

Diagram showing the range of two deep sky surveys done with the Hubble Space Telescope. The more distant the galaxy, the farther back in time we see. Young galaxies of the early universe are bluer from intense star formation than current galaxies are. Credit: NASA/ESA

Just as important, we can see where the stars are forming, helping us understand how galaxies like the Milky Way grew in size from small collections of very hot stars to the massive structures they are today. Crucially, with the addition of UV, we can now examine galaxies 5 and 10 billion light-years away from us, corresponding to a time period when most of the stars in the universe were born.